I had 2 clowns in my 30 gal tank with a BTA, a blenny,coralbeauty,some polyps, and some snail and crabs. I was informed that the glass top blocks to much light and that it would be fine not covered. Got up this morning and the smaller of the 2 (my fav.) jumped out and was dead when I woke up . They never payed attention to RBTA, will the other clown be ok they played alot? Would it be ok to replace him? Should i get a bigger or smaller clown? Whats the best way to cover my tanks to prevent this from happening but still get max light though.
Please help

You can get another clown if you want to. The best thing to do is get a clown that's smaller then the other just to ensure that it's a juvenille(in case the fish that didn't jump is a female). One thing you can do to prevent this in the future is get eggcrate(lighting diffuser) and put it over the tank to deflect the fish back into the water.

In my experience, if you don't have a lid, a fish WILL eventually end up on the floor. I lost a clown and a firefish. When I added a lid to the tank, my yellow tang still found a way out. It was a small opening in the back where a filter was, somehow, he accurately jumped through this tiny opening and ended up on to of the lid underneath the power compacts. He was baked by the time I got home ....
My cichlids take to the air from time to time....in the middle of the night I heard a loud splash, I didnt really think anything of it since they splash all the time so I went back to sleep. When I woke up, I noticed my large severum was not there. I found him dead behind the stand...ugh, it was tragic.
I now make sure that all the tank critters stay in the tank no matter what, which is a reason why I like the biocube- completely sealed. A lid for any aquarium is absolutely essential to prevent unnesessary fish deaths.

theres a few issues. getting a new clown may result in the one you have showing aggression. eggcrate works well to keep fish from jumping but IMO seems to also deflect a good amount of light. a wide netting attached to a frame lid will work good. as for firefish they are jumpers. period. if you wish to keep this fish you MUST have a lid, or else it will go carpet surfing. as for a tang in a 14 gallon cube, well thats an entirely new discussion.

no no no no no! I do NOT have a yellow tang in my 14 biocube!!! How could the tang have jumped out of a biocube? Are you familiar with biocubes? I was referring to my first saltwater tank which was 55 gallons. I would NEVER advocate keeping any fish like this in a small tank. I thought it was obvious I was referring to a different tank since biocubes do not have any openings in the back whatsoever. It was a 55 gallon tank that I used to have that I do not have anymore I put a glass lid on.

theres a few issues. getting a new clown may result in the one you have showing aggression. eggcrate works well to keep fish from jumping but IMO seems to also deflect a good amount of light. a wide netting attached to a frame lid will work good. as for firefish they are jumpers. period. if you wish to keep this fish you MUST have a lid, or else it will go carpet surfing. as for a tang in a 14 gallon cube, well thats an entirely new discussion.

I"ve never heard that eggcrate will decrease the par from the lights to the tank. If you get the silver coated maybe, but with the white only i've not heard anything negatively about it.

i also think egg crate will decrease/deflect lights. Even Glass Canopy do other than those made by Oceanic which increased intensity(wethe rit absorbed some wavelength, dont know). Used to make fence using plexi/acrylic on top of the tank and couple of hinges or hook on front panel for easy access to tank. Of course the lighting was hung from ceiling. This fence have prevented good amount of fish from tenpingt to fly/carpet dive..